Space Access and Technology
NASA's Reusable Launch Vehicle (RLV) program has dual objectives: to demonstrate technologies leading to a new generation of space boosters capable of delivering payloads at significantly lower cost, and to provide a technology base for development of advanced commercial launch systems that will make U.S. aerospace manufacturers more competitive in the global market.
Launched in 1994, the RLV program moved ahead on two fronts in 1996 with a restructuring of the X-34 air-launched small booster project and selection of a contractor for development of the larger X-33 technology demonstrator.
Under development by Orbital Sciences Corporation is the X-34, an experimental vehicle for testing technologies for a single-stage-to-orbit launch vehicle. First flight is targeted for 1998.
On June 10, 1996, NASA announced a program for the X-34 that will be a technology demonstrator rather than an operational system. Orbital Sciences Corporation (OSC), Dulles, Virginia was selected as prime contractor from among nine bidders.
The X-34 will weigh about 45,000 pounds and will be air-launched from a Lockheed L-1011 jetliner. The craft will be about 58 feet long and span about 28 feet.
The aim of the revised program is to create a reusable, suborbital test vehicle for demonstrating single-stage-to-orbit (SSTO) technologies, most of which have applicability in the X-33 program.
The X-34 plan calls for development of a vehicle capable of attaining a velocity of Mach 8 (roughly 5200 miles per hour), flying to an altitude of about 50 miles, and returning to an Earth base for a wheeled landing. The initial test flight must be made by October 1, 1998.
Among the technology areas the X-34 will explore is a very high flight rate: the vehicle must demonstrate potential for 25 flights a year. Other areas to be investigated are advanced thermal protection systems, a composite airframe, reusable propellant tanks, autonomous landing systems and advanced avionics.
OSC's development effort will be backed by a strong NASA/industry team. The X-34's propulsion system will be provided by Marshall Space Flight Center, which has been working since 1994 on an advanced liquid oxygen/kerosene rocket engine with a low-cost, partially reusable thrust chamber. The X-34 engine will have 60,000 pounds of thrust; since there is no requirement for attaining orbit in the test program, no second stage is needed.
In development for first flight in 1999 is the NASA/Lockheed Martin X-33 Advanced Technology Demonstrator, intended as the prototype of a 21st century low-cost-to-orbit reusable launch vehicle.
Ames Research Center will contribute thermal protection technology and Langley Research Center will handle computational fluid dynamics and aerodynamic testing.
Industry firms participating include AlliedSignal Aerospace, Torrance, California, which is developing advanced avionics and hydraulic power systems; Oceaneering Space Systems, Houston, Texas (re-entry thermal control); and Charles Stark Draper Laboratory, Cambridge, Massachusetts (navigation and guidance technology).
On July 2, 1996, Vice President Albert Gore announced the selection of Lockheed Martin Corporation for Phase II development of an experimental space booster that could become the prototype of a 21st century operational reusable launch vehicle (RLV).
The vehicle is the X-33 Advanced Technology Demonstrator, a half-scale version of the proposed operational system which, Lockheed Martin says, will be able to deliver 40,000 pounds of payload to low Earth orbit at a small fraction of the current cost of launching payloads to orbit. Under a cooperative agreement, the X-33 will be developed jointly by NASA and Lockheed Martin's famed "Skunk Works," noted for its success in creating such radical aerospace craft as the U-2 reconnaissance plane, the SR-71 Mach 3 research plane, and the F-117 Air Force stealth fighter.
The aim of the RLV program, NASA Administrator Daniel S. Goldin said at the announcement ceremony, is "to build a vehicle that takes days, not months, to turn around; dozens, not thousands, of people to operate; with launch costs that are a tenth of what they are now. Our goal is a reusable launch vehicle that will cut the cost of getting a pound of payload to orbit from $10,000 to $1,000."
Goldin underlined the fact that the RLV project represents a "radical departure" from the way NASA has done business in the past. In line with its mission of financing high risk developments in the interests of U.S. competitiveness and the national economy, NASA is funding the major share of the X-33 development, but the 21st century operational RLV will be developed on a commercial basis and NASA will become a user, rather than an operator, of the system.
NASA is providing $941 million through 1999 for the X-33; Lockheed Martin and industry partners will invest some $220 million in startup costs and initial R&D. The development will be carried out under a cooperative agreement-a true government/industry partnership-that is different from conventional contracts; it is a performance-based agreement under which NASA will make progress payments only when the industry team completes predetermined milestones.
The Phase II award-for design, construction and flight testing of the X-33-follows a 15-month Phase I concept definition effort during which each of three contractors developed its own design, operations plan and business investment strategy. After a lengthy evaluation of all the bids, Lockheed Martin was selected as NASA's industry partner over competitors McDonnell Douglas Corporation and Rockwell International.
Known as Venture-Star, the Lockheed Martin design is a wedge-shaped lifting body type of vehicle in which the entire airframe, not just the stubby winglets, generates lift. It is designed to be launched vertically and land horizontally like the Space Shuttle, but where the Shuttle uses conventional engines, a large throwaway fuel tank and drop-off boosters for launch, the X-33 will be totally reusable and employ what are known as "aerospike" engines. Built by Rockwell Rocketdyne, the engines offer utmost efficiency through a system that does not use conventional bell-shaped engine nozzles but automatically compensates for decreasing atmospheric pressure and regulates thrust as the vehicle ascends.
Lockheed Martin's industry partners include AlliedSignal, Teterboro, New Jersey (subsystems, avionics and operations support); Rockwell Rocketdyne Division, Canoga Park, California (aerospike propulsion); Rohr, Inc., Chula Vista, California (thermal protection system); Sverdrup Corporation, St. Louis, Missouri (launch site architecture and engineering); and Alliant Techsystems, Magna, Utah (fuel tanks).
The X-33 is being developed in a "fast track" program that envisions first flight in March 1999. An incentive clause provides a bonus if the Venture-Star can make 15 flights by the end of the century, at least one of them to a velocity of Mach 15. A successful X-33 program could lead to commercial development of a full-scale RLV and first operational use around 2005.